The first sign of debris from a missing plane that was carrying the Italian fashion executive Vittorio Missoni has surfaced on the Dutch Caribbean island of Curaçao.

A German tourist found a bag belonging to an Italian who missed the flight but whose luggage was on board the plane that vanished shortly after take-off on 4 January.

Curacao lies about 200 miles west of the resort islands of Los Roques, from where the BN-2 Islander plane departed for Caracas, the Venezuelan capital, with Missoni, three other Italian tourists and two crew members on board.

Norman Serphos, of the Curaçao prosecutor's office, said the German tourist had found the bag along the island's rocky north coast and contacted its owner in Italy, who in turn called police in Curaçao. Police received the bag on Friday and were working with authorities in Venezuela and Italy, Serphos said.

An official at the Italian embassy in Caracas said they were aware of the discovery.

Italy's air safety agency has said the pilot of the missing plane had an expired medical fitness certificate and the company operating the aircraft was not yet authorised to fly. However, the agency said neither factor was yet being blamed for the disappearance.

Seven minutes after take-off the pilot reported that he was at 5,000ft and 10 nautical miles from the Los Roques airport, according to the agency. The last radar readings showed the aircraft accelerating at 5,400ft before it quickly lost altitude and speed, veering to the right until it disappeared from the radar.